It is more than likely autoimmune.
She will be OK with proper treatment and follow up.
I am about to get my kids tested for thyroid issues as well due to the family history. I'd rather be on top of it then wonder if they will one day wind up like me.
The good news is that you caught it and it can be sucessfully treated.
Yes, the T4 was total and was marked low (normal range between 6-13). The pediatrician highly suspects Hashimoto's and is testing her autoimmune system in two weeks with her next TSH level. It's so overwhelming.
I am so sorry to hear about your daughter. The sleeping and delayed growth are signs, for sure. With treatment, I believe the growth will catch up.
Is the t4 level of 1.2 a free t4 or total t4 level. Is it marked as low? With a TSH that high, the free or total t4 will be very low, as it is severe/overt hypothyroidism.
Has she had thyroid antibodies checked? If not, I would request then at the next visit.
Hello, I am so sorry this is happening to your daughter and to your family. It seems like her main symptom is sleeping, and that is good that she is not having the other hypo symptoms. Of course, children, are able to bounce back better than adults.
Is an endo treating her? How often is s/he seeing your child?
Our prayers will go out for a speedy, complete recovery.